I just discovered this today. Seems they were especially popular during WWII.

I think I'm making stew tomorrow and I'm gonna make one of these with styrofoam and see how it goes.

Instructables Haybox Cooker

I read an old cook book from back in the 1800's.  They used hayboxes to cook in.  The book even had recipes for making paint and gun powder. 

I make stew in a crockpot that I let run all day long. The longer it slow cooks the better it tastes. I have doubt's this case stay hot enough long enough for me, but I'm sure it'll be cooked and okay.

This is supposed to be useful when you don't have access to fuel to spend hours cooking. It should save a lot on energy though.

Quote from: carlb on September 30, 2015, 08:33:34 PM
I make stew in a crockpot that I let run all day long. The longer it slow cooks the better it tastes. I have doubt's this case stay hot enough long enough for me, but I'm sure it'll be cooked and okay.

This is supposed to be useful when you don't have access to fuel to spend hours cooking. It should save a lot on energy though.

Slow Cookers and Energy Usage.

http://www.stretcher.com/stories/01/010528j.cfm

Quote from: carlb on September 30, 2015, 08:33:34 PM
This is supposed to be useful when you don't have access to fuel to spend hours cooking. It should save a lot on energy though.

Have you seen what some people in India use to cook with?  It's kind of a make-shift metal cone that uses the heat from the sun to cook meat, rice and vegetables.  I'll try and find the video where I saw that. 

Quote from: carlb on September 30, 2015, 05:48:45 PM
I just discovered this today. Seems they were especially popular during WWII.

I think I'm making stew tomorrow and I'm gonna make one of these with styrofoam and see how it goes.

Instructables Haybox Cooker

I remember my grand mother using this concept decades ago, it was a huge wooden box filled with sawdust.
OK, to a 6 year old it was huge.
She said it freed up the stove for cooking the rest of the meal, but never said what it was doing, and now I, "Have the rest of the story" (Paul Harvey).
Thanks for posting this, I never even thought about that till now, another unanswered question from decades gone by.